Without my knowledge, Adobe renewed my Creative Cloud subscription plan for one year.

You agreed to automatic renewal when you joined.  Professionals cannot afford to be without their tools. 

Check your account status online 24/7.

Please log-in to your account below.  Click Manage Plans > Cancel.
https://account.adobe.com/plans

NOTE:  To avoid 50% penalty fees for cancelling an annual plan early, wait to cancel until the 12th month of service after final payment is processed.  Set a reminder in your smartphone or desktop calendar app so you don't forget.

If you had read the terms of service, which no one does for anything, you might of noticed that the subscription would be Auto Renewed on the date next year of you Signing up.

There is no way to stop the auto renewal unless you cancel your subscription. For refund rules, refer the following link
https://helpx.adobe.com/manage-account/using/creative-cloud-subscription-terms.html
For steps on how to cancel your subscription, click the following link

https://helpx.adobe.com/manage-account/using/cancel-subscription.html

If it does not work then you will have to contact support. These are peer to peer forums and no one here has access to your account information. Click on the following link
https://helpx.adobe.com/contact.html
Make sure you are logged into your AdobeID, your browser has cookies enabled and no script blocker is enabled. Click on the chat icon on the bottom right.
Also be mindful of answering anyone who sends you a private message. See the following for more information about scammers
https://tinyurl.com/y7cfrr7y

-Manan